Flying Other Spirit creatures you control get +1/+1 and have hexproof. (They can't be the targets of spells or abilities your opponents control.)

Flying Whenever another Spirit enters the battlefield under your control, Mausoleum Wanderer gets +1/+1 until end of turn. Sacrifice Mausoleum Wanderer: Counter target instant or sorcery spell unless its controller pays {X}, where X is Mausoleum Wanderer's power.

Flash (You may cast this spell any time you could cast an instant.) Flying Whenever Nebelgast Herald or another Spirit enters the battlefield under your control, tap target creature an opponent controls.

Flash Flying When Rattlechains enters the battlefield, target Spirit gains hexproof until end of turn. You may cast Spirit spells as though they had flash.

When Skyclave Apparition enters the battlefield, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less. When Skyclave Apparition leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.